WT1在DNA损伤应答中的功能及诱导Wilms肿瘤的分子机制

Wilms’ tumor is the most common childhood kidney cancer and the disease-causing genes have been identified. Although the mutations of WT1 are associated with Wilms’ tumor development, as a transcription factor. the mechanism by which WT1 regulates gene transcription is not clear. In our previous work, using an unbiased protein affinity purification approach, we have found that WT1 associated with the RAP80 complex, a complex that targets BRCA1 to DNA damage sites and participated in homologous recombination (HR) repair. WT1 quickly relocates to DNA damage sites following DNA double strand breaks, suggesting that WT1 is involved in DNA damage response. Thus, we hypothesize that WT1 plays an important role in DNA damage response. Loss of WT1 leads the accumulation of DNA lesions, which induces genomic instability and tumorigenesis. To test our hypothesis, we plan to dissect the molecular mechanism of WT1 in DNA damage repair and study the functional defect of cancer-associated WT1 mutations, and explore the chemotherapeutic approach to WT1 mutation-induced Wilms’ tumor. Taken together, the results from the proposed experiments will allow us to understand the function of WT1 in DNA damage response and the molecular mechanism by which WT1 mutations induce Wilms’ tumor. It may also provide the scientific basis for the chemotherapeutics of Wilms’ tumor.

Wilms（威尔姆斯氏）肿瘤是最常见的儿童肾癌,WT1突变与Wilms肿瘤发生发展密切相关。作为一种转录因子，WT1通过何种机制调节基因转录从而影响肿瘤发生发展尚不清楚。我们前期通过蛋白亲和纯化方法发现WT1与RAP80复合物相互作用，该复合物靶向BRCA1至DNA损伤位点并参与同源重组修复（HR）。WT1在DNA双链断裂后会迅速迁移至DNA损伤位点，这提示我们WT1涉及DNA损伤应答。在本研究中，我们提出假设WT1在DNA损伤应答中起重要作用，WT1功能丧失导致DNA损伤积累，由此诱导基因组不稳定及肿瘤发生。为此，本课题拟研究WT1在DNA损伤修复中的分子机制及癌症相关的WT1突变引起的功能缺陷，并探索针对WT1突变诱导的Wilms肿瘤的化疗方法。总之，本研究结果将进一步了解WT1在DNA损伤应答中的功能及WT1突变诱导Wilms肿瘤的分子机制，同时也为Wilms肿瘤化疗提供科学依据。

Wilms（威尔姆斯氏）肿瘤是最常见的儿童肾癌,WT1突变与Wilms肿瘤发生发展密切相关。作为一种转录因子，WT1通过何种机制调节基因转录从而影响肿瘤发生发展尚不清楚。我们前期通过蛋白亲和纯化方法发现WT1与RAP80复合物相互作用，该复合物靶向BRCA1至DNA损伤位点并参与同源重组修复（HR）。WT1在DNA双链断裂后会迅速迁移至DNA损伤位点，这提示我们WT1涉及DNA损伤应答。在本研究中，我们通过实验发现过表达WT1会促进同源重组修复，WT1缺失导致DNA损伤积累，进一步证明WT1在DNA损伤修复中发挥重要作用。此外，在项目实施过程中，我们还发现WT1调控的p53蛋白的互作蛋白53BP1的突变体在DNA损伤修复中起作用且影响细胞增殖；同时WT1参与的HR通路中相关修复因子MDC1，TOPBP1及MCPH1的突变体影响DNA损伤修复和细胞增殖，并取得一定的进展。为我们后续的研究提供了坚实的理论基础。